The present invention relates to a method and apparatus for measuring the content of gas bubbles entrained in a flowing fluid.
In industrial applications involving the treatment of liquids, such as surfactant solutions, raw material reactants, lubricants, or polymer solutions, it often occurs that air or other gas bubbles are entrained in the fluid due to agitation, stirring or the like. Such entrainment of gas bubbles can lead to difficulties such as inaccurate flow rate measurements, nonuniformity of products, and the generation of noise. Also, in the case of lubricants, such as hydraulic oils, engine oils, turbine oils and the like, there may occur a reduction of hydraulic efficiency and an abnormal amount of wear of the parts to be lubricated.
The conventional approach to determining the content of gas bubbles entrained in such a fluid involves extracting from the flow of fluid a sample of known volume and subsequently weighing the sample or subjecting the sample to gas chromatography. Such methods, however, are disadvantageous because they are time consuming. They are also generally inaccurate due to the possibility of gas escaping from the container holding the sample. Thus, a method of measuring the gas bubble content of a flowing fluid without having to first extract a sample has long been desired.